The mechanics behind base capping are very simple. Winning by base cap, or using capping well however seems to confuse a lot of players. The two basic mechanics are…

Capping

Every individual player standing inside the red marked base box of an enemy base will add to depleting the capture bar of the base. Two players capping a base will be twice as quick as one, and four will be twice as quick as two. Always be aware though that whilst you’re standing in there, the rest of your team is a man down and still fighting, and that if they lose you are next. Also expect a welcome party. If the welcome party looks scary, consider leaving.

Blocking

A single player standing in their own base will block and prevent the capture, and stop any more of the bar from depleting. No matter how how many enemies. For as long as they survive and stay in the square, a single player will stop any number of enemies attempting to capture. Blocking is invaluable for buying time for reinforcements to arrive, or letting your team win their own cap first. If your bases capture bar is hanging around 10% and a loss is imminent, then get in that ring and last as long as you can, because otherwise it’s over anyway.

When your base is under attack

When considering a capture attempt, or when the enemy turns up at your base to do the same, you essentially have three options and things to consider.

Defend the base
You turn your metal arse round and rush back to save the day. You can either destroy the attackers, scare them off, or block the cap. If your metal arse moves at 100+ Kph, this might be a reasonable idea. If it belongs to an Atlas, and unless you’re really close, then it’s probably a bad idea, and you should keep your head in the fight or look for another way to win. One option being…

Counter Cap
Capture the enemy base first. This is possible, and often a good option. If your team has just rolled out and stomped the enemy, but missed that pesky commando which snuck round and got to your base whilst you’re all on the wrong side of the map, then you might want to try a counter cap. If his capture attempt isn’t more than half way done yet, you still have time to charge, as long as you do it together. Think about which base is closest, and who else is around you. (friendly and non friendly)

Keep fighting
Quite often you simply don’t have time to worry about a pesky capture attempt, and it’s a better idea to pay attention to the horde of bad guys bearing down on you. After all, you won’t be much help defending if you never make it there because a Jenner spotted you breaking off and melts your *** off first. Someone will need to do something though, so keep it in mind, and be ready to head to one of the bases if you need to.

Offensive Capping

I won’t write a full section on how to capture offensives, since if you know how to defend from them, then you know most of it anyway. It’s all the same principles. If you try for a cap alone and time it right, it may well work. Two players going for cap can hit hard and steal a game before the opposition can react, but leaves your team significantly short if things don’t turn out as planned. Attacking with a wave of heavies and assaults can be a very nasty surprise, but tricky and requires team co-ordination to work. And when going for a cap as a light, be wary of where the enemy lights are. If they catch you, you will likely be forced to fight them (since running from lights never goes well and only exposes your rear armour), so consider counting how many lights there are in your own team before heading out, to know how many speedy defenders might come to evict you.

Extra bits

Distractionary capping
Watch out for this one. Sometimes done on purpose, sometimes entirely unintentional, but often very effective. A base doesn’t actually need to be fully captured to ruin your game. If your base comes under threat, one of the most dangerous things to happen is often that people start spinning round and start to split up. By the time the Awesome and Centurion got back to base, I was long gone. By the time they got back to the fight, their team mates were long gone. A light pilot won’t always stick around a base to fight, but can just as easily come back when you get fed up of chasing. The best way around this stuff is to know who’s going where, and pick roles appropriately, so that you don’t have half you’re team go on a wild goose chase. This is tough to do in public games of course, but that’s just how the pursuit of teamwork goes.The shoot at the base myth
Shooting the little machine at the center of the base does nothing. It certainly does not speed up the capture, so don’t bother. It’s fun to do during a win, but that’s all.

Things not to do (And I’ve seen all of these in game, more than once in all cases)
– Don’t run all the way from the enemy base to your base in a misguided attempt to defend. Unless it’s come down to a one on one, this is almost always a waste of time.
– Don’t circle outside your base firing whilst a single armless centurion captures the last 20% of your bar. Get in there and block the capture.
– Don’t sit on the enemy base in a light mech and then try to fight the pair of mediums that turn up to defend. Unless you’re the kind who shouldn’t be reading this guide, you’ll lose and achieve nothing. You can always flee and rejoin the fight, or comeback to finish the cap latter. If you escape in one piece, you have at least wasted their time.
-Don’t turn your Atlas round the moment you see a base cap warning and get slammed in the back by the entire enemy team just as they come over the hill.

Yup. That’s all I can think of at present. Any more tips or comments bellow. I’ll try to check this thread to update it if needed, as long as it remains viewed.